BRPI0614181B1 - METHOD AND EQUIPMENT FOR LOCATING A WIRELESS LOCAL AREA NETWORK IN A LONG DISTANCE NETWORK - Google Patents

Abstract

Method and Equipment for Locating a Wireless Local Area Network on a Wide Area Network The description is directed to a mobile communication device that measures the characteristics and attributes of a first communications network that vary according to the physical location within the first communications network to create an impression or signature of a location within the first communications network. when the impression of the current location of the mobile device is created it may be compared to a known impression associated with a second communication network to determine the proximity of the mobile device with the second communication network. for example, the first communications network may be a cdma long-distance wireless communication network and the second communications network may be an 802.11 wireless lan.

Description

METHOD Ε EQUIPMENT TO LOCATE A WIRELESS LOCAL AREA NETWORK IN A LONG DISTANCE NETWORK

FUNDAMENTALS

FIELD

The present description generally relates to telecommunications, and more particularly, to systems and methods for supporting a mobile communications device capable of communicating through two different types of communication networks.

FUNDAMENTALS

The demand for wireless information services has led to the development of an increasing number of wireless networks. CDMA2000 lx is just one example of a wireless network that provides long distance telephony and data services. CDMA2000 lx is a wireless standard promulgated by the Third Generation Partnership Project 2 (3GPP2) using code division multiple access (CDMA) technology. CDMA is a technology that allows multiple users to share a common communications medium using spread spectrum processing. A competing wireless network that is commonly used in Europe is the Global System for Mobile Communications (GSM). Unlike CDMA2000 lx, GSM uses narrowband time division multiple access (TDMA) to support wireless telephony and data services. Some other wireless networks include the General Packet Radio Service (GPRS) which supports high-speed data services with data rates suitable for network browsing and e-mail applications, and the Universal Mobile Telecommunications System (UMTS), which can deliver broadband voice and data to audio and video applications.

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These wireless networks can generally be thought of as wide area networks employing cellular technology. Cellular technology is based on a topology in which the geographic coverage region is divided into 5 cells. Within each of these cells is a fixed transceiver base station (BTS) that communicates with mobile users. A base station controller (BSC) is typically employed in the geographic coverage region to control BTSs and direct communications to the appropriate access circuits for the various circuit-switched and packet-switched networks.

As demand for wireless information services continues to increase, mobile devices are evolving to support integrated voice, data and media on demand 15 while providing continuous network coverage between wireless wide area networks (WANs) and wireless local area networks (LAN). Wireless LANs generally provide telephone and data services across relatively small geographic regions using a standard protocol 20, such as IEEE 802.11, Bluetooth, or similar. The existence of wireless LANs provides a unique opportunity to increase the capacity of the user on a wireless long distance network by extending long distance communications to the unlicensed spectrum using the wireless LAN infrastructure25.

Recently, several techniques have been employed to allow mobile devices to communicate with different wireless networks. Additional techniques have been employed to allow a mobile device to scan for the presence of a wireless LAN to determine if one is available for connection. However, frequent or continuous search for a wireless LAN consumes energy unnecessarily and can quickly discharge the batteries in the

3/27 mobile device. As a result, improvements in power consumption and battery life for mobile devices can be made by intelligently searching for available wireless LANs.

SUMMARY

An aspect of a wireless communications device is described. The wireless communications device includes memory configured to store information regarding a first communications network, and a processor configured to determine whether the wireless communications device is in the vicinity of the first communications network based on information stored in memory and one or more reference signals from a second communications network.

Another aspect of a wireless communication device is described. The communication device includes memory configured to store information regarding a plurality of wireless LANs distributed over a WAN, and a processor configured to determine if the wireless communications device is in the vicinity of one of the wireless LANs based on information stored in memory and one or more WAN reference signals.

Computer-readable media embodying an instruction program executable by a computer to carry out a communications method is described. The method includes accessing information in memory, information about a first communications network, receiving one or more reference signals from a second communications network, and determining whether a wireless communications device is nearby the first communications network based on information accessed from memory and one or more reference signals from the second communications network.

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A method of communications is described. The method including accessing information in memory, information referring to a first communications network, receiving one or more reference signals from a second communications network, and determining whether a wireless communications device is in the vicinity of the first communications network based on information accessed from memory and one or more reference signals from the second communications network.

An additional aspect of a wireless communications device is described. The wireless communications device includes means for storing information regarding a first communications network, and means for determining whether the wireless communications device is in the vicinity of the first communications network based on the information and one or more reference signals. a second communications network.

It is understood that other modalities of the present description are within the scope of the detailed description below, where various modalities of the description are illustrated and described by way of illustration. As will be recognized, the description is capable of presenting other different modalities and several details can be modified in several other aspects, all without departing from the spirit and scope of the present description. Accordingly, the drawings and detailed description should be considered illustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the wireless communications system are illustrated by way of example and not by way of limitation, in the attached drawings, in which:

Figure la is a conceptual block diagram of a modality of a wireless communications system;

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Figure 1b is a conceptual block diagram of another modality of a wireless communications system;

Figure 2 is a functional block diagram illustrating an example of a mobile device capable of supporting both wireless LAN and long distance wireless communications; and

Figure 3a shows a flow chart of an illustrative method for creating prints on a mobile communications device;

Figure 3b shows a flowchart of an illustrative method for comparing impressions from different locations; and

Figure 4 shows a flowchart of an illustrative method for refining an existing impression to a known location.

DETAILED DESCRIPTION

The detailed description presented below with respect to the attached drawings serves as a description of the various modalities of the description and should not represent the only modality in which the description can be practiced. The detailed description includes specific details for the purpose of providing an in-depth understanding of the description. In some cases, well-known structures and components are illustrated in the form of a block diagram in order to avoid obscuring the concepts of the description.

In the detailed description that follows, several techniques will be described regarding the handoff of a mobile user from one network to another. Several of these techniques will be described in the context of a mobile communications device traversing over a long distance WAN with one or more wireless LANs spread across the WAN coverage area. The mobile communications device can be any suitable device capable of telephony

6/27 or wireless data communications, such as a cell phone designed for operation on a CDMA2000 lx network. The mobile communications device may be able to employ any suitable protocol to access a wireless LAN, including, for example, IEEE 802.11. While these techniques can be described in the context of a WAN phone capable of communicating with an IEEE 802.11 network, these techniques can be extended to other mobile communication devices capable of accessing multiple networks. For example, these techniques can be applied to a mobile communications device capable of switching between a CDMA200 0 lx network and a GSM network. Consequently, any reference to a cell phone capable of communicating with an IEEE 802.11 network, or any other specific modality, serves only to illustrate the various aspects of the present description, with the understanding that these aspects have a wide range of applications.

Figure la is a conceptual block diagram of a modality of a wireless communications system. A mobile device 102 is illustrated moving across a WAN 104 over a series of dashed lines. A mobile device 104 includes a BSC 106 supporting a number of BTSs dispersed throughout the WAN coverage region. A single BTS 108 is illustrated in Figure 1 for the sake of simplicity of explanation. A mobile exchange center (MSC) 110 can be used to provide an access circuit for a public exchanged telephone network (PSTN) 112. Although not illustrated in figure 1, WAN 104 can employ numerous BSCs, each supporting any number of BTSs to extend the geographical reach of WAN 104. When multiple BSCs are employed across the WAN 104, the MSC 110 can also be used to coordinate communications between the BSCs.

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WAN 104 can also include one or more wireless LANs dispersed across the region of long distance wireless coverage. A single wireless LAN 114 is illustrated in figure 1. Wireless LAN 114 can be an IEEE 802.11 network, or any other suitable network. Wireless LAN 114 includes an access point 116 for mobile device 102 to communicate with an IP network 118. A server 120 can be used to interface IP network 118 with MSC 110, which provides an access circuit to the PSTN 112.

When power is initially applied to the mobile device 102, it will attempt to access WAN 104 or wireless LAN 114. The decision to access a particular network may depend on a variety of factors regarding the specific application and general design restrictions. . For example, mobile device 102 can be configured to access wireless LAN 114 when the quality of service meets a minimum threshold. As far as wireless LAN 114 can be used to support mobile telephony and data communications, valuable bandwidth can be freed up for other mobile users.

mobile device 102 can be configured to continuously or periodically scan for a flag from access point 116, or any other access point on a wireless LAN. The flag is a periodic signal transmitted by access point 116 with synchronization information. The search for the WLAN flag requires that the mobile device, in turn, tune into possible WLAN channels, in one or more operating bands of a WLAN system, and conduct an active scan or a passive scan on the channel. In a passive scan the mobile device only tunes to the channel and receives for a specific period of time waiting for a transmission

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/ 27 of the flag. In an active scan, the mobile device tunes to the channel and transmits a probe request after following access procedures to avoid collision with devices in the channel. After receiving the probe request, the access point transmits a probe response to the mobile device. In the event that the mobile device 102 cannot detect a flag or does not receive any probe response to a request, which may be the case if power is applied to the mobile device 102 at location A, then the mobile device 102 attempts to access the WAN 104. With reference to Figure 1b, described later, mobile device 102 does not continuously (or periodically) scan a WLAN access point

but instead, sweeps a dot in WLAN access only when you determine that it is close to Wireless LAN 114. 0 mobile device 102 can access the WAN 104 getting one BTS pilot signal 108. Once what the pilot signal is

acquired, a radio connection can be established between the mobile device 102 and the BTS 108 by means well known in the art. Mobile device 102 can use the radio connection to BTS 108 to register with MSC 110. Registration is the process by which mobile device 102 reports its whereabouts to WAN 104. When the registration process is complete, the device mobile 102 can enter an idle state until a call is initiated, by mobile device 102 or PSTN 112. Either way, an air traffic connection can be established between mobile device 102 and BTS 108 to configure and support the call.

When mobile device 102 moves over WAN 104 from location A to location B in the mode shown, it is now able to detect a flag from access point 116. Since that

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9/27 occurs, a radio connection can be established between the two by means well known in the art. The mobile device 102 then obtains the IP address from the server 120.

mobile device 102 can use the services of a

Server

Name of

Domain (DNS) to determine address

Server IP. The domain name of server 120 can be distributed to mobile device 102 over WAN 104. With the address

IP, the mobile device establishes a network connection with server 120.

102 may i

Once the network connection is established, information from server 120 can be used in conjunction with local measurements to determine whether the quality of service of wireless LAN 114 is sufficient for the handoff of mobile device 102 to the access 116.

It should be noted that while figure la is generally descriptive of a cellular WAN, other WANs can be used. This can include those that do not use MSCs or other cellular structures, and WANs using other communication protocols including broadband CDMA (WCDMA), TD-CDMA, GSM or similar.

Referring now to Figure 1b, the wireless LAN

114 and BTS 108 are illustrated in the context of a larger WAN having multiple BTS 122, 124, 126 and also multiple

Wireless LANs 129, 131 and associated access points 128,

130. As illustrated in figure 1b, mobile device 102 is within the coverage area of any wireless LAN. Consequently, the search for a signal signal while there will be fruitless and consume energy unnecessarily. Although the mobile device can often go into an idle mode to conserve power, searching for wireless LAN beacon signals can quickly consume power. In a typical 802.11 network configuration, flag signals occur in

10/27 intervals measured in tens of milliseconds; therefore, the mobile device must remain awake and searching for at least that period of time per channel and considering that the wireless LAN access point can be configured for different frequency bands and channels within those ranges, the mobile device 102 must remain agreed a significant amount of time to search for available wireless LAN access points. Similarly, in the case of an active scan, the mobile device must remain awake to follow the channel access procedures on the channel, then transmit a probe request and remain awake to receive the probe response. You should conduct this procedure on each channel. In that case too, mobile device 102 must remain awake for a significant amount of time to search for available wireless LAN access points, which can result in increased power consumption and processing overhead.

However, by limiting the search for signal signals for periods in which the mobile device is within area 140, significant savings in energy consumption can be realized. Thus, when the mobile device 102 periodically wakes up to listen to the paging channel or a fast paging channel on the WAN, it can also determine its location. If it is determined that its location is within area 140, then it can search for a wireless LAN signal signal. Otherwise, you can avoid unnecessary search for the flag signal.

A mobile device 102 can monitor pilot and signal signals from WAN base stations. These signals can include paging and pilot signals. The mobile device monitors these signals to measure

11/27 primary and neighboring signal intensities to perform handoffs between base stations. In addition, in networks where the base stations are synchronized, the mobile device can also measure a phase of each pilot signal to assist in determining the handoff. Thus, at any location within the network 104, the mobile device 102 observes up to n base stations with measurable signal intensities that can be characterized as two vectors xi, ... , x _n , and yi, ..., y _n . Where each value of x is a signal strength of a pilot signal from a base station and each value of y is a phase of the pilot signal from a base station. When there are less than n, observed signals, the remaining values are determined to be zero. Since the pilot signals have a pilot phase shift associated with them, the signal strengths and phases can be readily identified as originating from a particular base station. In other WAN technologies such as GSM, neighboring base stations can be identified by their frequency channel or other base station identifier and a signal strength associated with each base station. In certain aspects, any signal used for acquisition, timing, or the like can be used as a signal that is used to obtain measurements to form one or more vectors described above. In addition, the vectors do not need to be formed, stored or used as two vectors as described, or include the information in the format described above. Thus, in some aspects, information that identifies a source and at least one characteristic of the reference signal, for example, paging or pilot signal, is used.

As is known in the art, the mobile device 102 monitors the beacon and pilot signals from the

12/27 base stations of the cellular network. These signals can include paging and primary signals. The mobile device monitors these signals to measure the primary and neighboring signal strengths to perform handoffs between base stations. In addition, in networks where the base stations are synchronized, the mobile device can also measure a phase of each pilot signal to assist with the determination of the handoff. Thus, at any location within the network 104, the mobile device 102 observes up to n base stations with measurable signal strengths that can be characterized as two vectors xi, ..., x _n and yi, ..., y _n · Where each value of x is a signal strength of a pilot signal from a base station and each value of y is a phase of the pilot signal from a base station. When there are less than n observed signals, the remaining values are set to zero. Since the pilot signals have a pilot phase shift associated with them, the signal strengths and phases can be readily identified as originating from a particular base station. In other WAN technologies such as GSM, neighboring base stations can be identified by their frequency channel or other base station identifier and a signal strength associated with each base station.

In WCDMA, base stations may not be synchronized. As in CDMA, when the mobile is idle on the paging channel of a particular base station, it scans the signals from the neighboring base station. In the case of CDMA, each base station uses deviations from the same pseudo-random scattering sequence. In the case of WCDMA, each base station transmits a number of signals designed to allow the mobile station to quickly acquire synchronization with the signals transmitted by that base station and once synchronized determine the group

13/27 spreading code and the spreading code in use by that base station. The scattering code set and its signal strengths can be used to create the fingerprint to identify a location on the WCDMA cover corresponding to the pilot shifts and pilot signal strengths in the CDMA system. Relative timing deviations from neighboring base stations can also be used corresponding to the pilot phases in CDMA, however, if the base stations are not synchronized, their clocks may have a relative deviation making the timing deviation an unreliable indicator.

The information can be used as an impression concept, or a signature, of a location on the mobile device 102. Thus, if the locations within area 140 have a certain known impression, then the mobile device can determine its current impression and compare the same with the known impression to determine whether the mobile device is located within area 140. While the above discussion merely mentions the use of two WAN attributes (ie, pilot signal strength and phases). Additionally, as discussed above, other dynamic attributes of the WAN can be used instead of, or in combination with, these two attributes. For example, pilot offset values can be used as an impression; even the number of available pilot signals is a possible attribute to be used for an impression. In addition, the attributes that create the impression need not necessarily be attributes of the WAN. For example, many mobile devices have GPS receivers that can be used to determine the location of the mobile device in relation to a wireless LAN. GPS information can be used directly or

14/27 even indirectly. As an example of the latter case, a base station ID together with the phase measurements of the GPS signals from different satellites can be used to define an impression that corresponds to a location of the mobile device. Thus, in its broadest sense, an impression is a collection of attributes of a first communication network that change based on location and can be used by the mobile device to determine the proximity of a second communication network.

In addition, printing can also include characteristics of the transmitters of the second communication networks (for example, MAC ID,

Band, Channel, Information

RSSI of WiFi access points). In such a case, the parameters

WAN can be considered as trigger parameters so that a combination of the parameters triggers a search

WLAN. The WLAN parameters can be used during the search as the search parameters for the triggered search.

Attributes can be calculated in a variety of different ways without departing from the scope of this description. For example, an instantaneous measurement can be performed of such attributes as pilot signal strength and phase and used as an impression. However, even when the device values these environmental attributes. Consequently, performed together or, if I moved this stationary, the variations due to the variation multiple measurements can be otherwise, combined in some statistically significant way in order to generate the impression.

Figure 2 is a functional block diagram illustrating an example of a mobile device capable of supporting both WAN and wireless LAN communications. The mobile device 102 may include a WAN transceiver 202 and a wireless LAN transceiver 204. In at least one

15/27 mobile device mode 102, the WAN transceiver 202 is capable of supporting CDMA2000 lx, WCDMA, GSM, TD-CDMA or other WAN communications with a BTS (not shown), and the wireless LAN transceiver 204 is capable support IEEE 802.11 communications with an access point (not shown). It should be noted, that the concepts described in relation to the mobile device 102 can be extended to other WAN and wireless LAN technologies. Each 202 transceiver,

204 is illustrated with a separate antenna 206, 207, respectively, but the 202 transceivers, 204 can share one only broadband antenna. Each antenna

206, 207 can be implemented with one or more radiation elements.

The mobile device 102 is also illustrated with a processor 208 coupled to both transceivers 202, 204, however, a separate processor can be used for each transceiver in the alternative modalities of the mobile device 102. Processor 208 can be implemented as hardware, firmware , software or any combination thereof. For example, processor 208 may include a microprocessor (not shown). The microprocessor can be used to support software applications that, among other things, (1) control and manage access to the wireless long distance communication network and wireless LAN, and (2) interface the processor 208 with the keyboard 212 , monitor 210, and other user interfaces (not shown). Processor 208 may also include a digital signal processor (DSP) (not shown) with a built-in software layer that supports various signal processing functions, such as convolute encoding, cyclic redundancy check (CRC) functions, modulation, and spectral spread processing. The DSP can also perform functions

16/27 vocoder to support telephony applications. The way in which processor 208 is implemented will depend on the particular application and design constraints imposed on the system as a whole. It should be noted that the hardware, firmware and software configurations can be interchangeable under these circumstances, and how best to implement the functionality described for each particular application.

Processor 208 can be configured to execute an algorithm to trigger a handoff from one network to the other. The algorithm can be implemented as one or more software applications supported by the microprocessor-based architecture discussed above. The module can be implemented in hardware, software, firmware or any combination thereof. Depending on the specific design restrictions, the algorithm can be integrated into any entity on the mobile device 102, or distributed across multiple entities on the mobile device 102.

For certain purposes known in the art, the signal strength of the access point can be measured on the mobile device 102 with a received signal strength indicator block (RSSI) 216. RSSI is most likely a measurement of the strength of an existing signal which is fed back to the wireless LAN transceiver 204 for automatic gain control, and therefore can be delivered to processor 208 without increasing the complexity of the mobile device circuit 102. Alternatively, the quality of the radio connection can be determined from the flag. Since the flag is one. spread spectrum signal which is known beforehand, a replica of the flag can be stored in memory 211 on the mobile device 102. The demodulated flag can be used with the flag

Duplicate stored in memory to estimate the energy of the signal transmitted by means well known in the art. '

With reference again to the previously mentioned impressions, the mobile device 102 also includes an algorithm executable by the processor 208 for creating multiple impressions and comparing the different impressions with each other. For example, using a keyboard 212, a user of the mobile device 102 can select a key that causes the mobile device 102 to create a current impression and store that impression in memory 211. If at the time the impression is created , the mobile device is connected to a wireless LAN, then the stored print can be associated with that wireless LAN access point. In addition, the impression can also be automatically recorded periodically or at scheduled events such as successful access, successful access with the desired quality of service, etc.

As a result of the above process, memory 211 may contain a wireless LAN lookup table arranged, for example, similarly to the following table:

WAN ID WLAN SSID BSS WLAN ID Signal strength Phase THE 11 There Si (Al). . . Y _n (Ai) Pi (Ai) Pn (Al) A ₂ Si (A ₂ ). . . s _n (A ₂ ) Pi (A ₂ ) Pn (A ₂ ) 12 to ₃ Si (A ₃ ). . . s _n (A ₃ ) Pi (A ₃ ) Pn (A ₃ ) B 11 Bi Si (Bi). . . s _n (Bi) 12 b ₂ Si (B ₂ ). . . s _n (B ₂ )

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The first column of the table refers to the WAN ID of the WAN. The WAN ID identifies the system and network for the WAN known as the SID / NID in the wireless long distance system. The particular base stations on the WAN can be identified by pilot offsets, pilot signal strengths and other attributes that are part of the impression as discussed below. The printout identifies the location of the mobile device. The second column refers to the text identifier for the WLAN network. The third identifier 10 refers to wireless LAN access points (also known as BSS). In the illustrative table there are three access points (A _x , A ₂ , A ₃ ) within the first coverage area of base station A. Similarly, there are two access points within the coverage area of base station B. You can obviously, there will be more wireless LANs within the areas covered by any WAN ID but the mobile device user may not be interested in these access points as they are associated with wireless LANs that the user may not be allowed to access. Therefore, the table may merely include an impression for the access points to which the user typically connects.

The remaining two columns include the values that comprise the print itself. In this illustrative table the impressions for the access points Ai, A ₂ , 25 A ₃ include both intensity and phase information. However, the impressions for access points Bi and B ₂ comprise only the signal strength information. It is also worth noting that although each impression in this table is denoted by a vector of length n, there may be 30 less than n non-null components of the vector. That is, several values can be null so that the print comparison is restricted to the vector components that are not null. In operation, a mobile device can be

19/27 awake in an idle or dormant way and calculate an impression for your current location and compare it with the information in columns 4 and 5 in the table. The mobile device typically limits the print combination to records corresponding to the WAN ID with which it is currently registered. Thus, when registered with WAN ID A, only the impressions associated with WAN ID A in the table are used for matching. The creation, and comparison of impressions can occur during call progress as well. Based on comparison, the mobile device can determine that an access point with SSID and BSSID indicated in columns 1 and 2 is close enough to search for its flag signal; otherwise, you can return to idle mode without worrying about looking for a wireless LAN beacon signal.

The table above is illustrative in nature and does not describe all of the possible information that can be used to characterize a print or all of the different combinations of WAN IDs versus access point IDs. For example, since most areas are covered by multiple WAN service providers, each with their own WAN ID (SID / NID), a table record for an access point can occur multiple times associated with different WAN IDs. with a respective signature on each. In addition to the table presented above, a separate table (or possibly additional records in the original table) can be used to store information about the corresponding access point (ie, BSS ID). For example, a wireless LAN access point is typically configured to operate on a particular channel in a particular frequency band. Rather than requiring a mobile device to search through different possible combinations, the table can contain operational information for the

20/27 access so that the mobile device can use it to search for the signal signal. Other information about the access point may include its capabilities such as security, quality of service, performance and network information.

The creation of the printing table is described with reference to the flowchart of figure 3a. In step 302, the mobile device connects to a wireless LAN. Without the benefit of any pre-stored prints, the mobile device scans for a WLAN access point in the typical way. Once the mobile device has connected to the access point, the user can, in step 304, signal the device to capture the current impression. This step can typically be initiated by the user since the user may wish that only certain wireless LANs are stored in the print database such as the wireless LANs that the user normally signs or connects to. However, the creation of an impression can be initiated automatically by the mobile device as one of several steps performed when connecting to the wireless LAN.

In step 306, the mobile device captures the values for those attributes that comprise the impression, and in step 308, the device stores the impression in a database. Along with printing, it is also advantageous to store the attributes of the currently connected wireless LAN.

The comparison of a current impression with a stored impression can be done in several ways without departing from the scope of the present description. A particular technique is described below. However, many alternative techniques, but functionally equivalent, can be used as well.

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The attributes that create the impression can have values that vary (even for the same location) or are difficult to measure with a high degree of accuracy. Therefore, a comparison between impressions should not be based on exact duplication as a test for determining a combination. Similarly, region 14 0 may reflect an operational decision to give more importance to detecting access points earlier at the expense of false alarms. In other words, if region 140 is selected as being much larger than region 114, then a mobile device 102 will determine that it must search for one flag signal at a time when it is not within region 114 (that is, an alarm false). If, however, region 140 is selected to be a very close copy of region 114, then there will be cases in which the mobile device must search for a flag signal but the print matching algorithm has not yet instructed it to search.

To deal with such variability of impressions, an amount of deviation is defined that helps control whether a print matches a stored print.

ID WAN ID WLAN BSS Intensity Deviation from Intensity Phase Phase Shift in signal THE There Si (Ai) . ..s _n (Ai) ditAJ. • d _n (Ai) Pi (Ai). . • Pn (Ai) qi (Ai) q _n (Ah Si (A ₂ ) . . .s _n (A ₂ ) di (A ₂ ). • d _n (A ₂ ) Pi (A ₂ ). . • Pn (A ₂ ) qi (a ₂ ) q _n (A ₂ ) A ₃ Si (A ₃ ) . . .s _n (A ₃ ) di (A ₃ ). • d _n (A ₃ ) Pi (A ₃ ). . • Pn (A ₃ ) qi (a ₃ ) q _n (A ₃ )

The table above includes a deviation value for the signal strength and a separate deviation value for the

22/27 part of printing phase. The use of these values is explained in relation to the flowchart in figure 3b. In step 320, the mobile device wakes up or is otherwise controlled to capture an impression of its current location. Continuing with the example in which the print has a vector of signal intensities and one for phases, a pair of vectors is collected x _lz ... x _n and yi,. . . , y _n .

In step 322, the current WAN ID is verified and the table records for the access points associated with that WAN ID are determined. Additional search refinements are made possible by searching the database for observable pilot identifiers. For the CDMA network, the search criterion may be the PN phase deviations of the observable pilots. Next, the impression for each of these access points is compared, in step 324, with the current impression to determine whether a combination exists. Algorithmically, the comparison and determination is performed by:

for i = 1 to n:

determine whether | xí-s ± (·) | <d ± (·) determine whether | yi-pi (·) I <q ± (·)

In this way, the deviation values d and q can be used to select how far the current impression (vectors x and y) should approach a stored impression (vectors s and p). The higher the deviation values, the more the values can differ and there will still be a combination.

If there is a combination in step 324, step 32 6 an optional comparison can be made to determine whether the sum of all differences for a given access point (for example, | xí ~ Sí (·) | and | yi- pi (·) I) are below a respective limit (for example, X and Y). This additional test can help if you realize

23/27 certain situations in which individual differences may show a combination but when the impression is considered in total, it can be determined that there is no such combination.

If the tests in steps 324 and 326 are satisfied for a LAN access point in the table, then the mobile device is controlled in order to search for signal signals from that access point. If there is no match at steps 324 and 326, the mobile device continues to search for a match or other impression for another BSS ID. In a case where possibly more than one hotspot impression matches the current location impression, then the sizes of the differences, or the sum of the differences, or some other determination can be made to select the access point with the impression that most closely matches the current impression. In this case of multiple combinations, when the mobile device scans for WLAN access points it can locate one or more access points.

Figure 4 presents a flowchart of an illustrative method for refining a print record. In step 402, the mobile device, after searching for and acquiring the signaling signal, connects to the wireless LAN access point as is known in the art. The access point has a MAC address that is used as its BSS ID. Other identifiers can be used to differentiate between different access points; however, the BSS ID is a convenient value. Thus, in step 404, the mobile device determines whether the access point to which it is connected has a record in the impression table. If not, a current impression can be generated (see figure 3a) and then stored, in step 406. If a print record already exists for the access point,

24/27 then the current impression can be used to refine the stored impression, in step 408. As part of the refinement process, the deviation values, if present, can be refined as well, in step 410.

The refinement process uses the current impression to modify the stored impression in such a way that the stored impression, instead of merely representing the first time the access point was discovered, actually benefits from the values measured during several times when the access point was discovered. access point was discovered. An example of such a refinement can be described with reference to the signal strength parameter but it applies equally well to the phase parameter or any other attribute that is used to create the impression. According to this method, a record of the number of times the impression has been updated is also kept. In this example, the impression for the Αχ access point is updated for the K-th time. The impression includes the vector Sx (Αχ). . . s _n (Αχ) and the current impression includes the vector x _x ,. . ., x _n . Each sector s value is updated according to the formula:

new Si = [(K-l) (old Si) + x ±] / K

This type of medium refinement is merely illustrative in nature and there are many acceptable mathematical techniques that can be used to refine a present print value without departing from the scope of the

be performed by adding values for a new attribute (for example, the number of measurable pilot signals) to printing rather than, or in addition to, changing existing values.

Deviation values can be refined as well. For example, the initial deviation values can be a standard value. Like, for example, 10 dB (for

25/27 signal strength) or the default value for a deviation can be variable such as 5% of the print value. In this example, the deviation vector measured between the xes vectors is a vector nii, ..., m _n . The new deviation value di is calculated by MAX [(previous di), mi, (default di / SQRT (K))].

In the examples above, the mobile device generates the prints and stores them in a print database. However, some or all of the prints can alternatively be stored elsewhere further up the wireless long distance network such as a database 111 accessible by the MSC 110. In this case, the processing requirements and storage requirements can be reduced to the mobile device. During operation, the mobile device would create a current impression and transmit that impression to the MSC (or BSC possibly if the database was located there). The MSC would then perform the print comparison and instruct the mobile device to search or not for an access point signal. In this arrangement, the MSC would receive impressions from multiple mobile devices and would have a much larger database of available access points than would be found on a single mobile device. Alternatively, a custom print database can be created for each user of the wireless long distance network and stored on their main system.

The various logic blocks, modules, circuits, elements and / or illustrative components, described in relation to the modalities described here can be implemented or carried out with a general purpose processor, a digital signal processor (DSP), an integrated circuit of specific application (ASIC), a field programmable port arrangement (FPGA) or other

26/27 programmable logic component, discrete gate or transistor logic, discrete hardware components, or any combination of them designed to perform the functions described here. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any processor, controller, microcontroller or conventional state machine. A processor can also be implemented as a combination of computing components, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other similar configuration.

The methods or algorithms described in relation to the modalities described here can be implemented directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. A storage medium can be coupled to the processor so that the processor can read information from, and write information to, the storage medium. Alternatively, the storage media can be integrated into the processor.

The previous description provides certain aspects and illustrative modalities. Several modifications to these modalities and aspects are within the scope of the description and the generic principles defined here can be applied to other modalities. Thus, the claims should not be limited to the modalities illustrated here, but the full scope consistent with the language claims, where

27/27 reference to an element in the singular does not mean one and only one unless specifically mentioned, but instead one or more. All structural and functional equivalences to the elements of the various modalities described throughout the description that are known or that will become known to those skilled in the art are expressly incorporated herein by reference and should be encompassed by the claims. In addition, nothing described here should be dedicated to the public 10 regardless of whether such a description is explicitly recited in the claims. No claim element shall be considered under 35 USC § 112, sixth paragraph, unless the element is expressly mentioned using the phrase means for or, in the case of method claim 15, the element is recited using the phrase step to.

Claims (14)

1. Communications method for a wireless communications device (102), characterized by the fact that it comprises: create an impression for a first communications network (114) by capturing a value of at least one attribute of at least two reference signals transmitted by at least two base stations (108, 122, 124, 126) on a second network communications (104) when the wireless communications device (102) is in close proximity (140) to the first communications network (114), the print comprising values of at least one attribute captured from each of the at least two base stations (108, 122, 124, 126); store the printout in memory (211); receiving at least two other reference signals transmitted by at least two base stations on the second communications network (104); and determining whether the wireless communications device (102) is currently in the vicinity (140) of the first communications network (114) by comparing a current value of the at least one attribute of the at least two other reference signals from the second communications network (104) with the value of at least one attribute in the print stored in memory (211). 2/5 more reference signals to determine if the wireless communications device (102) is in the vicinity (140) of the first communications network (114). 2. Method according to claim 1, characterized by the fact that it additionally comprises creating the impression by detecting the first communications network (114) during a search. 3/5 the value of at least one attribute in the printout stored in memory (211). 3. Method, according to claim 1, characterized by the fact that it additionally comprises using relative phase information from the one or more Petition 870190016580, of 02/18/2019, p. 7/11 4/5 the value of at least one attribute in the stored impression. 4. Method according to claim 1, characterized in that it further comprises using relative signal strength of one or more reference signals to determine whether the wireless communications device (102) is in the vicinity (140) of the first communications network (114). 5/5 wireless communications device (102) is in the vicinity of the wireless LAN (114, 129, 131), the print comprising values of at least one attribute captured from each of the at least two base stations (108, 122, 124, 126); and means for determining whether the wireless communications device (102) is currently in the vicinity (140) of one of the wireless LANs (114, 129, 131) by comparing a current value of at least one attribute of at least two others reference signals received from the WAN (104) with the value of at least one attribute in the print stored in memory (211). 5. Method according to claim 1, characterized by the fact that the one or more reference signals comprise pilot signals. Method according to any one of claims 1 to 5, characterized in that the first communications network (114) comprises a plurality of wireless LANs (114, 129, 131), and the second communications network comprises a WAN (104) covering wireless LANs (114, 129, 131), further comprising: create and store in memory (211) a printout for each wireless LAN (114, 129, 131) by capturing a value of at least one attribute of at least two reference signals transmitted by at least two base stations (108, 122 , 124, 126) on the WAN (104) when the wireless communications device (102) is in the vicinity of the wireless LAN (114, 129, 131), the printout comprising values of at least one attribute captured from each at least two base stations (108, 122, 124, 126); and determining whether the wireless communications device (102) is currently in the vicinity (140) of one of the wireless LANs (114, 129, 131) by comparing a current value of at least one attribute of at least two other received from the WAN (104) with Petition 870190016580, of 02/18/2019, p. 11/11 Method according to any one of claims 1 to 6, characterized in that the determination of whether the wireless communications device (102) is currently in the vicinity (140) of the first communications network (114) is performed by comparing the difference between the current value of at least one attribute and the value of at least one attribute in the impression stored in memory (211) and a predefined offset. 8. Wireless communication device (102), characterized by the fact that it comprises: means (208) for creating an impression for a first communications network (114) by capturing a value of at least one attribute of at least two reference signals transmitted by at least two base stations (108, 122, 124, 126) on a second communications network (104) when the wireless communications device (102) is in the vicinity (140) of the first communications network (114), the print comprising values of at least one attribute captured from each of the at least two base stations (108, 122, 124, 126); means (211) for storing the print; means for receiving at least two other reference signals transmitted by at least two base stations on the second communications network (104); and means (208) for determining whether the wireless communications device (102) is currently in the vicinity (140) of the first communications network (114) by comparing a current value of the at least one attribute of the at least two other signals. reference from the second communications network (104) with Petition 870190016580, of 02/18/2019, p. 9/11 Wireless communication device (102) according to claim 7, characterized in that it additionally comprises means (208) for using relative phase information from one or more reference signals to determine whether the wireless communications (102) is in the vicinity (140) of the first communications network (114). Wireless communication device (102) according to claim 7, characterized in that it further comprises means (208) for using relative signal strength of one or more reference signals to determine whether the wireless communication device wire (102) is in the vicinity (140) of the first communications network (114). Wireless communication device (102) according to claim 7, characterized in that the one or more reference signals comprise pilot signals. 12. Device wireless communications (102) , in according to any one of claims of 8 to 11, characterized by the fact in that the first network in communications (114) comprises a plurality of LANs without (114, 129, 131), and the second communications network comprises a WAN (104) covering the wireless LANs (114, 129, 131), the wireless communications device (102) further comprising: means for creating and storing in print (211) a print for each wireless LAN (114, 129, 131) by capturing a value of at least one attribute of at least two reference signals transmitted by at least two base stations (108 , 122, 124, 126) on the WAN (104) when the Petition 870190016580, of 02/18/2019, p. 11/10 13. Wireless communications device (102) according to any of claims 8 to 12, characterized in that the means for determining are operable for determining whether the wireless communications device (102) is currently in the vicinity (140) of the first communications network (114) by comparing the difference between the current value of at least one attribute and the value of at least one attribute in the print stored in memory (211) and a predefined offset. 14. Computer-readable memory, characterized by the fact that the method according to any one of claims 1 to 7 is recorded in it.